Classic computing fanatic Alejandro Valero has created a clone of the ill-fated Jupiter Ace microcomputer with a distinction: it is boosted to specs and options of which the unique designers may have solely dreamed, together with high-resolution video and 528kB of user-accessible reminiscence.
“Launched in 1982, Jupiter Ace is among the least identified private computer systems of the home computing period. Even thought its business life was brief and it by no means achieved the success of different up to date system, these of us who noticed the increase of private computing within the ’80s bear in mind the Jupiter Ace because the machine with a novel strategy, because it was based mostly on Forth as a substitute of BASIC,” Valero explains.
“These days,” Valero continues, “greater than 4 a long time after, I’ve determined to create a clone which is aesthetically as shut as potential to the unique, with out attending to the purpose of being a precise copy, by getting an understanding of the {hardware} to the purpose of permitting me to make modifications that add extra energy to it, and extra importantly, to study alongside the best way.”
The Jupiter Ace was a product of Jupiter Cantab, a Cambridge-based microcomputer firm based by Richard Altwasser and Steven Vickers to compete with the Sinclair ZX80 — constructed by their former employer Sinclair Analysis. The choice to make use of Forth when most rival machines of the period used BASIC, the supply of the far cheaper Sinclair ZX81, and the discharge of the full-color ZX Spectrum noticed the Jupiter Ace fall by the wayside — and the corporate went bankrupt after only one yr in operation.
Valero’s Mercury Ace, then, is the Jupiter Ace that might have been — a fully-compatible clone, based mostly on an present design of Grant Searle and present schematics, which affords a wealth of upgrades. The usual 1kB of user-accessible RAM has been boosted to a whopping, by Nineteen Eighties requirements, 528kB, cut up into 16kB on-board and 512kB in an add-on module, together with 32kB of textual content RAM and 32kB of character RAM; there is a high-resolution video mode, once more by the period’s requirements, of 256×192; there’s video shadow RAM assist; and software-selectable ROM paging, all housed in a duplicate case.
The PCB matches in an unique Jupter Ace housing, or a 3D-printed duplicate, with an elective add-on board for high-res video and 512kB extra RAM. (📷: Alejandro Valero)
Valero wasn’t alone within the design: along with these talked about above, Valero had help from Pedro Gimeno in designing the PCB and high-resolution add-on board, and Gimeno additionally the ROM; the case, in the meantime, relies on one launched by Cees Meijer — with a couple of tweaks. The venture additionally has the blessing of Paul Andrews, whose firm acquired the rights to the Jupiter Ace in 2015.
Extra data on the venture is out there on Hackaday.io, whereas Valero has revealed all the pieces you want to construct your individual in a Codeberg repository below the reciprocal GNU Normal Public License 3.
